Ignition Coil Usage on Series III XJ6

In 'Lucas Parlance':
XJ6 4.2 1970 - 1978 = DLB102 Coil
XJ6 4.2 1979 - 1985 = DLB198 Coil
XJ6 4.2 Auto 1970 - 1979 = DLB102 Coil
XJ6 4.2 Auto 1980 - 1986 = DLB198 Coil

Jeb Boyd:
It is my understanding that the DLB 102 is a replacement coil, not the original. The DLB 101 is for points ignition, and is a twelve volt internally ballasted coil and the DLB 102 is an externally ballasted six volt coil for electronic ignitions. The correct coil is a Ducelier (French) coil and has a history of failure. I have always used the DLB 102 to replace it. I don't know if the DLB 198 is the Lucas number for the Ducelier coil or not.

Doug Dwyer:
I replaced the Ducellier coil on my 1987 (USA) XJ6 with the DLB198 and have had no problems.

Michael Neal:
A leaking coil brought an important issue to mind. At VIN 412543 on North American XJ6s Jaguar found fit to change to a ballast resistor type coil along with a revised amplifier and harness. Note that the ballast resistor is not a bypass resistor! It is always inline to the coil. The coil is French made Ducellier with a Unipart label stuck over the top of it. They are prone to leakage and are often replaced with a cheaper unit. Jaguar retails the proper unit at around $130. The only reason that I have found so far for the coil change is to protect the amplifier by limiting the input voltage to the coil. Unless you are willing to take a good chance of spiking your ignition amplifier I would recommend using the expensive Jag unit. Several people on the jag-lovers mailing list have used aftermarket coils and rigged an external ballast resistor. So far there have been no problems so this does seem to be a viable alternative. Usually the culprit in a spiked amplifier is a faulty distributor pickup. Always replace the pickup if the amplifier is blown. I had several cars come back with the amplifier blown after a initial replacement. Did some checking in the service records and found that almost every car that only had the faulty amplifier replaced came back for another. I even found one that had three amps in 5 years. Now that I've been replacing the amps and pickups as a pair I have had no returns! A word of warning on leaking coils. The oil may contain PCBs which are very hazardous to your health! Wear latex gloves like the professional Jag techs do. Good quality latex gloves are available for around $5 a box. A very necessary accessory for working on your oily Jag.